


Seperated Bones

by Roses_winter100



Category: Underfell - Fandom, Undertale (Video Game), underswap
Genre: Alternate Universe - Gaster Blaster (Undertale), F/F, F/M, Gaster Blaster Papyrus (Undertale), Gaster Blaster Sans (Undertale), How Do I Tag, M/M, i can't tag, technical baby blasters
Language: English
Status: In-Progress
Published: 2020-07-14
Updated: 2020-07-15
Packaged: 2021-03-04 23:06:48
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 3,508
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25254304
Author URL: https://archiveofourown.org/users/Roses_winter100/pseuds/Roses_winter100
Summary: The worst sound a skeleton could wake up to is their bones snapping.~~The skeletons are hiding something, no one expected it to be this big.
Relationships: Alphys/Undyne (Undertale), Asgore Dreemurr/Toriel, Grillby/Grillby (Undertale)
Comments: 13
Kudos: 46





	1. Chapter 1

The worst sound a skeleton could wake up to is their bones snapping.

Sans wriggled helplessly on his mattress as his body crackled and shifted, he knew what was happening he just didn’t expect to wake up in the middle of the night to it.  
The tiny monster tried his best to relax before the transformation reached his ribs, spinal cord and skull, they were the worst parts.  
Sans shoved his pillow in between his teeth to muffle any noises he would make; a small thud came from the room next door telling the smaller skeleton that his older brother was shifting too.  
His mind went blank as his skull snapped and sharpened, five horns forced their way out of the back of his head, his lower face extended with muffled crunches and his teeth ripped his pillow into shreds as they sharpened and grew longer.

His night clothes burst and ripped as his spine grew sharp spikes in a wave, the spikes were about as long as sans’ phalanges and seemed to be controllable as they flicked up and down. From his shoulder blades grew long hand like appendages with an incredibly thin see through membrane connecting the ‘fingers’.

His shorts didn’t stand a chance as his legs thickened and reshaped to look more like the legs of a velociraptor, his tail bone continues the wave from the spine to make a tail longer than sans was tall. At the tip of the skeletal tail was eight longer needle-sharp spikes, four on each side.

His shoulders shifted and his arms became front legs, his thumbs elongated to match the rest of his fingers as they became sharper than razors and dug into the bedding.  
His feet crackled as they grew longer, his smaller toes settled in the middle of the feet, the big toes became claws much like those of a velociraptors, his other toes also sharped like his fingers and dug into his bedding.

His head now resembled a horned reptile, his body was now very feline in structure, his back legs and spinal cord were very prehistoric.

A Gaster Blaster.

Sans softly dropped the remains of his pillow and tugged his claws out of the mattress. The smaller skeleton sat on his hunches too rest his front paws on the wall leading to Papyrus’ room before making a soft near-silent bird-like whistle, an equally as soft warble came from the other room.

Paps was okay.

Thankfully, the brothers ignored Toriel's suggestion on getting doorknobs instead of handles as Sans slid his tail around it to tug it down before pushing the door open with his new snout, the older skeleton met him in the hallway by bumping their muzzles together.  
Papyrus when sitting up straight could scrap the top of the door frame with his top horn, while sans hardly reached the handles. The taller skeleton looked incredibly similar to sans, albeit sharper in appearance and missing the wings.

The two bone puppies slowly crept past the master bedroom which held the goats and the room a cross it holding the reptile couple, the two rooms across from the skele-bros rooms were a bathroom and toilet.

The two brothers froze when they heard shuffling from inside the reptiles room, the floor boards in front of the door gained a shadow that had Papyrus leaping from the floor to above the doors, his claws digging into the tops of the frames to hold him in place while Sans just scaled the wall before curling slightly near the ceiling. A half asleep Alphys stumbled out, using her phone as a flashlight to guild her down the stairs as she probably stumbled her way to the half-supplied kitchen, past all the boxes and the front door.

The door that the skeletons wanted to leave through.

Sans used his magic to plant the two of them onto the ceiling like lizards as they scurried towards the stairs.

They didn’t expect Alphys to return so quickly, or for her to notice them and scream.

Someone flicked all the lights on, and everyone rushed out from their rooms.  
The two skeletons dropped to the floor and shot down the stairs as Undyne threw a spear at them.  
“W-wait, they just scared me t-they m-might be f-fr-friendly!” Alphys squealed, Undyne stopped and squinted at the larger skeletal creature as it attempted to hide behind a pile of still-packed furniture.  
“their skeletal… Can someone get Sans and Papyrus please?” Toriel asked, Frisk went to run upstairs before freezing and turning back around to stare at the two bone-puppies.  
“Frisk? What’s wrong Darling?” Mettaton asked as the child hopped back down the stairs.  
The child puffed their cheeks a pressed their palms on them making a farting sound.  
The smaller skeleton popped up from the boxes and repeated the sound with bright blue and yellow eye-lights.  
“h-how did it d-do t-that? It d-doesn’t have a tongue..”  
The child giggled before making grabby hands at the bone-dragon-puppy-thing.  
Sans looked at his brother who hesitantly nodded, the smaller then leapt over the boxes with incredible ease despite the height difference and bunny hopped to the ten-year-old.  
‘Sans’ they signed before wrapping their arms around the skull the best they could, the beast chirped and clicked.  
Papyrus crept out from their hiding spot and stood next to Asgore and whistled, making the two goats and fish jump, once the older skeleton knew that the royals were paying attention to him, he bowed.  
“Papy…?” Undyne whispered, getting a soft warble in return as the orange and green eye-lights sparkled towards her sharp yellow one.  
“p-P-02-1-WDG?” Alphys muttered, reading the rough engravings in the taller skeletons arm  
“S-05-WDG.” Mettaton read as well, the similar carving in Sans’ collar bone.  
“Serial numbers?” Asgore mumbled, scratching absentmindedly at Papyrus’ top right horn.

Papyrus then gently caught the edge of the kings sleeve in his teeth, pulling the goat toward the front door and knocked it twice with his muzzle with a gargle.  
“you want to go outside?” he chuckled, slowly unlocking the large wooden door.  
“grrrack” Papyrus rumbled back before clicking in Sans’ direction having the smaller ‘bunny hop’ over to them.  
“I’d assume so.” Toriel giggled as Sans climbed his brother to sniff at Asgore’s shoulder.  
The larger goat pulled the double doors open and stepped to the side just in time to dodge the skeletons as they shot outside, sans using his brother as a spring-board, the two stopped and looked back at the group they were living with before sprinting off into the forest covering the mountain.

“they have some questions to answer when they get back.” Undyne muttered as her father figure pushed the doors shut once more, her girlfriend hummed in agreement.  
~~~~~`  
I got overly bored so I know this is probably terrible, I also have no beta reader for my Undertale stories.  
if you enjoy it, 'yay' if you don't 'that's fine, thank you for being here'  
this will most likely be continued though criticism is appreciated. {ps please inform me of any spelling mistakes :) }


	2. Chapter 2

**Notes for the Chapter:**

> Chapter two! I'm sorry it's so short >_<

Sans easily ran in front of the larger beast, being more aerodynamic than the other. The scenery around them blurred as they ran faster than the newest racing motorbike. The ground under them lost the grass and moss of the forest as they ran further up the mountain, the trees thinned and became sparce as the creatures slowed down. The two climbed to the tip of the mountain and looked up at the stars.

Sans started with a deep rumble before lifting their skull and howling.  
The sound echoed throughout the night like sharp winter winds, Sans’ cry was a mix of a wolf howl, an owl screech and a roar of something long dead.  
As the younger brother ran out of air the elder threw his skull back and continued the call.

Papyrus’ cry was more of a roar than a howl, but it had the same effect as it evened out into the winter wind screeches like Sans’ did.  
The two howled for hours on end, singing to the stars, to the darkened sky and to four others who couldn’t sing with them.  
As the sky lightened the singing faded, for their audience had left. The two slowly trotted back down the mountain, what took them a minute to run up, took three hours to trot down.  
The two hopped over the four-and-a-half-foot high fence hiding the back yard with incredible ease, the larger blaster stretched much like a cat and yawned broadly before crawling under the porch and curling into a ball for a nap.  
Sans watch his older brother settle down to sleep but found himself to energized to join him and instead entertained himself by playing with the large exercise ball - that Undyne and Papyrus use for soccer – like it was made of yarn, he kept his pointy bits and his strength in mind so he wouldn’t pop it.  
Soon sans dropped the ball and softly jogged up to the kitchen window overseeing the porch and peeked in to see Toriel and Asgore preparing for breakfast, the male goat spotted him first and jumped slightly before chuckling, Toriel too chuckled seeing the rather muddy skull of her friend.  
Asgore stood and shuffled towards the back door, sans leapt from the porch, picked the large ball back up and ran to the sliding backdoor as the ex-king stepped out into the frosty early morning air.  
“Good morning Sans.” He rumbled, in reply Sans dropped and nudged the ball towards him before bouncing back and play bowing.  
“Oh? want to play do you?” He chuckled Sans barked, his whip like tail wagging furiously.  
“Alrighty then.” The ex-king shrugged off his sleeping gown and toed off his slippers before scooping the muddy grey ball into his arm and walking over to one side of the large yard.  
The two played a bazar game of volleyball/fetch until breakfast was ready.  
“What are you two doing!” Undyne roared playfully as she ran outside, Sans-who seemed to grow more energetic and excited as the game went on leapt at her with a loud semi-bark.

“WiBBle wIbBLE!!” the skeleton blurted as he ran a circle around the fish lady.

“Wibble Wibble! Huh Wibble Wibble!” the captain yelled back “What a silly puppy you are!~”   
Sans jumped at her, getting rough rib rubs in return for the strange hug. “Where’s your brother?”  
Sans dropped down and Undyne gripped a part of his jaw near the back that had no teeth and shook his head, “Breakfast is ready, do you want food? Then go get your brother!~”  
The smaller skele-puppy ran off and Undyne turned to the fatherly goat “was that Sans or Papyrus?”  
The man chuckled full-heartedly “I believe that was Sans.”  
“he’s playful like this.”  
“and you would make a good mother.”  
“Wh-What no-pftt that’s funny.”  
Sans ran back to the single-eyed lady with his tail wagging at breakneck speeds, a much larger, broader and groggy skele-puppy slowly followed with a wide yawn.  
“both of you are really muddy, Asgore could you go grab some towels please?”  
Undyne guided the over excited and very sleepy bone dragons over to the hose and turned the water onto low pressure, she gently washed the mud off of Papyrus first as he was the dirtiest of the two, using the split in the bottom jaw as a guide the prehistoric fish monster pulled the larger undead onto the porch where Asgore was waiting to pad him dry.  
Now the hard part, Undyne decided to take a smart approach and turned the hose onto high pressure and sprayed it in a straight line. Sans did all the hard work by playing in the water, dislodging the mud by himself, turning the hose off, Undyne tapped the porch twice and sans hopped up to be dried off by king fluffy buns.  
Once both the skeletons were dry the four went inside where the rest were waiting Alphys had two large bowls filled with everything from breakfast for the skeletons in case they didn’t want to turn back.  
Sans slipped ahead of the others and sat in front of the yellow reptile, soon joined by his older brother. They were given their bowls and Alphys went and sat down at the table.

“Why aren’t they eating?” Mettaton whispered to Asgore-who shrugged in reply.  
Undyne waited for a few seconds before, “Okay!”  
Sans shoved his face into the smaller bowl and accidentally wacked Papyrus with his tail.  
Papyrus ate slower, his tail wasn’t wagging as fiercely as the younger, but he was still seemed pretty happy.  
Undyne looked a bit put off as she slid her egg around the plate with a sigh.

“Wha-what’s wrong?” Alphys asked, sipping at her black coffee.

“Their trained. Someone’s trained them like dogs.” She growled, with a huff she looked down at her now snapped in half fork. “How old are they? Does anyone know? I never thought about it until now.”  
~~~~~~~~~~~`  
To Be Continued :D  
semi-cliffhanger :P -again sorry for it being so short  
please inform me of spelling mistakes and constructive criticism is appreciated.


	3. Chapter 3

**Notes for the Chapter:**

> this chapter is a little longer :)  
> i hope you enjoy.

Silence covered the group like a thick blanket besides the soft scrapes of bone against plastic as the two bone-puppy-dragons scoffed down their food.  
“they have to be at least somewhere in the three hundreds. Four at minimum for sans.” Mettaton laughed nervously, the robot had never been all that good with monster children and the ghost piloted robot got along great with the two skeletons.

Sans finished his food before looking up at the group muttering to themselves and huffed.  
The smaller warbled at the larger who grunted, Sans waited for Papyrus to finish before the two went upstairs.  
Because It was by chose, the transformation back to being bipedal caused the two no pain.  
The two met in the hallway, fully dressed in their usual everyday clothes, Papyrus then scooped his younger brother into his arms and slowly walked back downstairs to the living room where the two settled on the large couch, both of them needed a nap.

~~~~`

Alphys watched as the two skeletons left and heard what sounded like Papyrus come back down the stairs.  
Quietly the lizard got up from the table and wondered into the living room where the two undead monsters were snuggling into the couch, the yellow monster grabbed the throw blanket and tucked them in before going back into the kitchen.  
“I-I know a way to f-f-find out the-their e-exact a-age…” she stuttered, Frisk looked excited and signed 'how?'  
“I need a-ha a bone fragment f-from b-both of them and I um put the f-f-fragments in a machine that tells me their stats and a-age and um p-p-parents…and uh and soul traits…” she murmured  
“that would be great Alphys, Thank you.” Torial beamed.  
“I-I can g-get the ah the fragments n-now, they're asleep on the couch.” The reptile whimpered, wringing her claws together.  
“What can we do to help?” Undyne chirped, beaming at her girlfriend.  
“can you a-and frisk go down t-to my lab and get a scalpel and t-two vials p-please?” Alphys shyly grinned back.  
“And miss Torial could you b-be ready to heal them? they shouldn’t feel it but better safe then um ah sorry, r-right?”  
“Of course.” The ex-queen smiled softly.  
The human child and the fish monster quickly returned with what was asked of them, the female goat and reptile quietly moved into the living room.  
Alphys gently scrapped the scalpel down Papyrus’ bare arm and collected a teaspoon worth of bone fragments. She did the same on Sans’ leg, getting the same amount.  
The reptile then guided the group down into the basement that was renovated into a makeshift laboratory before starting up the machine that she was talking about.  
“this is ah an interesting way to s-start the day huh?” Alphys muttered as they waited for it to start up.  
“definitely.” Undyne laughed boorishly.  
Alphys gently unloaded half of the dust collected from Papyrus into the machine as the others talked around her, it took a minute to process until it beeped, and words appeared on the screen.

“Name: Orange Papyrus Gaster-Didn’t know that.  
Soul trait: Bravery-perseverance-didn’t know that either  
Parents: unknown-what?  
At: 20  
Def: 20  
Hp: 680- a little low is it not?  
Lv: 0-that’s good  
Age: 239  
Bio: The second oldest in a family of six. A sweet child with more secrets than one his age should know; he misses his twin. He remembers.” Undyne read aloud, her fin-ears pressed back, and she look guilty. “I was training a child to be in the royal guard.”  
“do sans now.” Asgore grunted, he was curious and forgot to watch his tone which he quickly apologized for.

“Name: Blue Comic Sans Gaster-why colours?  
Soul trait: Patience-justice-determination -he’s got three traits! - D-D-Determination!? Th-that’s unhealthy for a monster!  
Parents: unknown  
At: 1  
Def: 1  
Hp: 1  
Lv: 0  
Age: seven-…78  
Bio: She’s the baby in a family of six yet knows more secrets than anyone her age; she misses her eldest sibling. She remembers.”   
Undyne whimpered to herself. “he-she’s just a babe she’s should still be nursing!”  
“And her Hp! Such a low number should have her hospitalized!” Torial cried into Asgore’s shoulder.  
“The h-hp is probably f-f-from being weaned s-so early, t-too e-early.” Alphys explained, tears were also in her muddy green eyes.  
Undyne broke away from the group as they murmured and sulked to each other, to jog back upstairs. She knew what she was going to do-what she had to do, Asgore himself said she would make a good one this morning. Time to prove him right.  
As she walked down the hall towards the living room, the fish lady stopped at the linin cupboard and fished out a thick, soft fleece blanket, her magic seemed to have heard her thought process and hummed around her like bubbles rising from the bottom of a lake. Her pheromone level increased slightly, and she tried to not think of the new development. She smells like a mother-to-be.

Throwing the fleece blanket over her shoulder, the Fish danced around the kitchen, milk in the microwave warming and a recently washed ketchup bottle was filled with the steaming milk when it was at a temperature she was content with. Entering the living room, Undyne froze slightly at the sight the two undead made on the couch and a soft smile stretched across her face.

Gently removing sans from hi-her older brothers grasp before tucking Papyrus back in, Undyne gently wrapped the baby-bones - her baby-bones in the fleece blanket and rested her against her chest, it didn’t take long for the little one to catch the scent of the milk-filled ketchup bottle being held in front of her teeth. Undyne allowed the tiny hands to latch onto her much larger one to be guided towards the sleeping little one’s mouth, the fish mentally pat herself on the back for not flinching at the sound of very sharp milk teeth scratching against the plastic as the babe nursed.  
Slowly she nuzzled into the crown of her skull, scenting her new baby as hers, Undyne was her mother, Sans was her baby. Papyrus would need a nuzzle as well but he’ll get his later.  
Alphys waddled in and smiled softly at the sight of her girlfriend feeding the baby skeleton, the fish hadn’t noticed the lizard yet as she was still nuzzling her scent onto the fragile bone. The scientist shuffled over to the elder skeleton and softly nuzzled into his skull as well, Adopting him into their bazaar little family. The scientist was apparently the new ‘father’ for them.

“We’re going to adopt the other four when we find them, right? ‘family of six’ and all.” Undyne whispered, easing the empty bottle away from the full skeleton, without her hoodie Sans…Blue was tiny, the hoodie puffed her up in a way that made her look fat-sorry ‘big-boned’ when really she was smaller-thinner than frisk. 

Well add flesh and they would be the same size but that’s not the point.

“o-of course. ‘The m-more the m-merrier’.” Alphys squeaked back, softly taking the young child from her girlfriend to scent her as her own as well. Even the small doctor could hold the hoodie-less skeleton one handed. Once both of the new parents had scented their new children, Blue was tucked back in with Orange to continue their nap. The older females completely unaware that Orange had been awake since they were covered by the throw blanket during breakfast. He was just playing dead, something all skeletons were incredibly good at.  
He had heard everything that happened in the dining room and basement and felt his orange magic fill up his sockets, he could still feel the rough scales scratching against his skull and blue was softly nursing on his sweater neck. They might not have their brothers back, but they had mothers now, two mothers willing to take all of them.  
~~~`  
To be continued


End file.
